Answer:
b. increased efficiency in walking as forests transformed to wooded environments; the ability to carry food in order to provision family members.
Explanation:
Peter Rodman and his colleague proposed a 'patchy forest hypothesis' according to which forests become more patchy and the food in them is in dispersed form so, the hominids their can move efficiently with energy and can carry food now with free hands.
While Owen Lovejoy suggested that monogamous males, provision their females and protect them from predators, females that are provided with foods, could now take care of more than one offspring at a time, and thus reduce the gap between births.